Study on microscopic identification of Astragalus complanatus and A. adsurgens seeds

Astragalus adsurgens seed is one of the most common adulterants of Astragali Complanati Semen in the market, whose morphological characteristics are very similar with A. complanatus seeds (Astragali Complanati Semen). Many identification methods have been reported, such as morphological identification, fluorescence method, ultraviolet spectrophotometry, TLC, HPLC, protein electrophoresis and so on, but there's no much about microscopic identification. In the present study, the morphological characteristics and microscopic characteristics of these two seeds were investigated, which could provide scientific evidence for the identification and classification of Astragali Complanati Semen. Our results showed that these two seeds were slightly different in the color and the appearance, but significantly different in the microstructure of the seed coat and the hilum, and the distribution of fat droplets in the cotyledon cells. So these microscopic characteristics can be applied for the identification of Astragali Complanati Semen.